20 DR. FARADAY'S EXPERIMENTAL RESEARCHES IN ELECTRICITY. (SERIES XI.) 



lated, will give signs of electricity, opposite in its nature to that of A, and therefore 

 caused by induction, although the influencing and influenced bodies cannot be joined 

 by a right line passing through the air. Or if, the electrometers being removed, a 

 point be fixed at the back of the ball in its uninsulated state as at C, this point will 

 become luminous and discharge the conductor A. The latter experiment is described 

 by Nicholson *, who, however, reasons erroneously upon it. As to its introduction 

 here, though it is a case of discharge, the discharge is preceded by induction, and 

 that induction must be in curved lines. 



1231. As argument against the received theory of induction and in favour of that 

 which I have ventured to put forth, I cannot see how the preceding results can be 

 avoided. The effects are clearly inductive effects produced by electricity, not in 

 currents but in its statical state, and this induction is exerted in lines of force which, 

 though in many experiments they may be straight, are here curved more or less ac- 

 cording to circumstances. I use the term line of inductive force merely as a tempo- 

 rary conventional mode of expressing the direction of the power in cases of induction; 

 and in the experiments with the hemisphere (1224.), it is curious to see how, when 

 certain lines have terminated on the under surface and edge of the metal, those 

 which were before lateral to them expand and open outfrovn each other ^ some bending 

 round and terminating their action on the upper surface of the hemisphere, and 

 others meeting, as it were, above in their progress outwards, uniting their forces to 

 give an increased charge in the carrier ball, at an increased distance from the source 

 of power, and influencing each other so as to cause a second flexure in the contrary 

 direction from the first one. All this appears to me to prove that the whole action is 

 one of contiguous particles, related to each other, not merely in the lines which they 

 may be conceived to form through the dielectric, between the inductric and the in- 

 ducteous surfaces, but in other lateral directions also. It is this which gives the 

 effect equivalent to lateral repulsion or expansion in the lines of force I have spoken 

 of, and enables induction to turn a corner (1304.). The power, instead of being like 

 that of gravity, which relates particles together through straight lines, whatever 

 other particles may be between them, is more analogous to that of a series of mag- 

 netic needles, or to the condition of the particles considered as forming the whole 

 of a straight or a curved magnet. So that in whatever way I view it, and with great 

 suspicion of the influence of favourite notions over myself, 1 cannot perceive how the 

 ordinary theory of induction can be a correct representation of that great natural 

 principle of electrical action. 



1232. I have had occasion in describing the precautions necessary in the use of the 

 inductive apparatus, to refer to one founded on induction in curved lines (1203.) ; 

 and after the experiments already described, it will easily be seen how great an in- 

 fluence the shell-lac stem may exert upon the charge of the carrier ball when applied 

 to the apparatus (1218.), unless that precaution be attended to. 



* Encyclopaedia Britannica, vol. vi. p. 504. 



